Multiple outlet fluid pump and control



July 22, 1952" T. STOYKE MULTIPLE OUTLET FLUID PUMP AND CONTROL 3 Sheets-Sheet 1 Filed Dec. 10, 1949 July 22, 195 1.. T. STOYKE MULTIPLE OUTLET FLUID PUMP AND CONTROL Filed Dec. 10, 1949 3' Sheets-Sheet 2 NNN y 1952 L. T. STOYKE MULTIPLE OUTLET FLUID PUMP AND CONTROL Filed Dec. 10. 1949 3 Sheets-Sheet 3 .Q ANN Patented July 22, 1952 MULTIPLE OUTLET FLUID PUMP AND CONTROL Ludwig T. Stoyke; Rockford, $111., assignor to Sundstrand Machine Tool Co., a corporation of Illinois Application December 10, 1949, Serial No. 132,2ii3' 11 Claims.

This invention relates to. pumps and more par ticularly to variable displacement multiple out-. let fluid pumps. a

--It is the general object of this invention to produce a multiple outlet variable displacement. pump ofnew and improved design.

Itis a more specific object of this invention to produce controlmeans for a variable displacement multiple. outlet pump adapted to vary the displacement of the pump in response to a'variable control pressure.

A further object of the invention is to produce a control device for a multiple outlet variable displacement pump operating when the pressure in any single. outlet exceeds a predetermined amount toreduce; the displacement of the pump.

Still another object of the invention is to produce 'a control device for a pump of the type described in the preceding paragraphs in which a variable control oil pressure isemployedfor operating means for controlling the displacement of the pump and where means, movable in response to the build-up of excessive pressure in any outlet, is provided in the variable contro oil circuit to tank control pressure.

It is. a further object of the invention to 'produce a pump for use with a control of the type described. in the preceding paragraph whichis provided with means biasing the pump toward zero displacement and which the means: for controlling displacement operate in opposition to the biasing means. t

Other and further objects; oftheinvention wiil become apparent from theqfol-lowing. description and drawings, in which: 1

Fig. l is a longitudinal section'through a fluid pump housing and discharge manifold embodying the invention; r I

Fig. 2 is a schematic diagram of the hydraulic control circuit, showing in section the pump, and the relief, relay and priming valves; I

Fig. 31s a sectional view of the outlet pressure relief. valve showing the details thereof; and

Fig. 4 is an enlarged view of the upper portion. of'Fig. 1 showing the details of the relay valve Pump construction mounted in the casing and carries a Wobbler device 1? for converting rotary motion of the shaft into reciprocatory movement; of the pistons. A valve device it; is provided for controlling the flow of fiuidgto the cylinders from an inlet port l9 and from the cylinders to a plurality ofdis,-

charge ports 28', one of which latter ports is provided .for each of the cylinders 13'.

The cylinder block I2 is generally annular in form and has an integral flangezl positioned between the casing sections I'll and ll, the casing sections and flange being secured together by a plurality of bolts 22. The cylinder block is provided with a cylindrical recess in its right hand end (asshown in. Figl) to form a cylindricalvalve chamber 23. having opposed parallel end faces 2 andZ 5. In this chamber and against, these faces, the valve device It is located.

The shaft It is rotatably mounted within, the casing and to. this end there are provided a roller bearing 2% and a ball bearing 21 at the left hand endof the casing and a roller bearing 28 supported in the cylinder block l2, which bearings carry the shaft. The Wobbler device ll; comprises an inner ring member 29 which is pivotally mounted on the shaft 5-5 by means of a pin 33 extending thereth-rough. The Wobbler includes an outer ring 3,! carried onthe innerring by means of roller bearings 3-2 and thrust bearing 32a and is arranged with a flat end face 33 in position to engage the adjacent convex ends of the pistons M. As will be noted from the drawings, the pin 39. about which the. Wobbler pivots is oiT center with respect to the central longitudinal axis of the shaft til and with respect to the Wobbler face. Thus, as shaft 16 is rotated an inertia load is applied to the Wobbler, tending to rotate it about the pivot to a position imparting maximum stroke to the pistons. This inertia load is augmented by the hydraulic load applied. to the pistons, as will be hereinafter described, and thus the Wobbler tends to assume a position causing maximum stroke with rotation '01" the shaft It.

Springs 3% arelocated in an annular recess 35 between the cylinder block and the casing H], and are secured to an annular collar 36 which in turn is, adapted to contact the ring 33 to urge the Wobbler to neutral position. By compressing the springs and thus moving the collar 36 to the right, the wobbler assumes a stroke-imparting position as described. For compressing the springs I mount them in a sleeve 31 slidable in the recess 35. Thesleeve is provided with a shoulder 38 located in a chamber 39 formed between the sleeve and an annular member 40 secured in fluid-tight relationship to the casing I9 by a number of O-rings 40a. A fluid passage 4| is connected to the chamber 39 and to a main relay control valve 42 which is adapted to supply operating fluid under pressure thereto to move the sleeve to the right to compress the springs.

Each of the pistons has a relatively larger portion 43 adjacent its left hand end (as seen in Fig. 1) and a relatively smaller portion 44 adjacent its right hand end. The cylinders I3 are so proportioned as to engage each of the sections of the piston, and accordingly the right hand section 45 of each cylinder has a somewhat smaller diameter than the left hand end. The proportioning of the pistons provides an annular shoulder surface 46 on each piston to which oil pressure is applied to urge the pistons to the left'on their intake strokes, as hereinafter described.- i I The valve i8 is positioned with its annular rim portion 48 in the valve chamber 23 between the cylinder ports and the radially aligned discharge ports 20 opposite thereto. The valve is given a gyratory movement by means of an eccentric pin 49.which is carried on a rotatable shaft 59 positioned in axial alignment with the shaft l6 and connected thereto by a spline arrangement The valve I8 is freely rotatable about the eccentric pin 49. and is provided with a, perforated valving rim,- the perforations taking the form of i a plurality of openings 52 therethrough adapted to interconnect each of the cylinder ports with a predetermined different one of the discharge ports 29. The valve itself is more specifically described in,the copending application of myself and. Bruce, H. Mossbaker filed on December ,10, 1949, as SerialNo. 132,292, now'Patent No.

Movement of the pistons on their return, or suction stroke is accomplished by means of a gear pump 53 mounted upon the shaft 59 and connected by means of a passage 54 to a groove 55 in each of the cylinders [3. The groove 55 is locatedat the mean position of the shoulder portion 46 and thusthe pressure generated by the pump 53 serves constantly to urge the pistons to the'left, that is, on their suction or return strokes. Pump 53 also serves as the source of fluid pressure for operating the control system to be hereinafter described.

Where Wobbler type pumps are used as fuel pumps for engines using crude oil as the fuel, impurities in the crude oil often cause the deposit of scale or' other accumulations on the pistons. Such accumulations are apt to cause sticking of the pistons. I have found that accumulations of this nature are usually encountered only in a comparatively small area near the high pressure end of the piston. In order to remove such deposits I provide means for introducing a solvent therefor at the area most likely to be affected. To this .end I provide a conduit 5'6 which may be connected to a source of solvent under pressure, which conduit connects with an annular groove 51 formed in the sidewalls of the smaller portion 45 of the cylinder. A second annular groove 58 is also provided in that portion of the cylinder spacedoutwardly, that is, to the right as seen in Fig. 1, from the groove 51. The annular groove 58 connects with a conduit 59 which empties into the inlet side of the pump. Solvent is introduced into the conduit 56 at a pressure somewhat less than the pressure of'fluid from the pump 53 so that no tendency exists for the solvent to leak into the operating oil circuit. The solvent covers the area of the piston which reciprocates between the annular grooves to remove all accumulations which might otherwise foul the piston, and is removed through the conduit 59 to the intake side of the pump. The annular groove 58 and the conduit 59 also serve to return to the inlet any fuel on the high pressure side of the pump which leaks past the outer end of the piston.

In the particular embodiment shown eighteen pistons are provided in the pump which discharge into an equal number ofdischarge ports 29. The end cap H is provided with a manifold arrangement 90 designed to combine the eighteen'discharge ports into six separate outlets by joining three ports equally spaced in the discharge port circle to form six groups of three discharge ports each. To this end themanifold is provided with six annulargrooves 6i, separated by O-rings 62. Slots 93 are milled in the manifold to'connect'each discharge port 29 to one of the six annulargrooves 6|. Six discharge outlets 64-69 are provided, each connected-to one of the slots 63.

Pressure relief valve lte ferring" now to Fig.2 of the drawings, I pro;

vide a pressure relief valve 19 in the operating fluid circuit between thegear pump 53 and the groove 55, which valve is provided with a bore .1! having a piston 12 reciprocable therein, and urged by means of a spring 13 toward the left,

as seen in Fig. 2. Means in the form of a screw device 14 is provided for adjusting the tension of the spring to determine the pressure at which the relief valve opens. The piston 12 is pro vided with a plurality of openings l5 through the sidewalls thereof adapted when the piston is moved to the right under the pressure of oil in a chamber 16, to which the pump' 53 is connected, to be align ed with an annular groove 71 in a sleeve 18' positioned at the left hand end of, the bore. The sleeve is provided with a number of notches 19 connected to the groove 11 and opening to' the interior of the bore. A conduit 89 opens at one end to the interior of the bore I! and at the other end to the interior of the casing H1. The relief valve 10, of course, determines the upper limit of operating oil pressure in the'cirwit and serves to tank oil under pressure sufficiently 'high to compress spring 13 and cause rightward movement of the piston 72.

Main relay control valve The conduit 54 is connected to the chamber 15 and to the space and, by means of an intermediate conduit 8i, to a main relay valve 82. 'I'herelay valve is provided with a bore 83 to which the conduit 8| opens and'with a piston I A slidable sleeve 99 is located in an intermediate portion of the bore and providedwitha plurality of openings 91 controlledby a-al-andtgslocated connected to' an annular groove I I8 which in turn onthe left hand end of thepiston 84. The openings 9I extend radially through .;the sleeve and are connected by means "of an annular groove 93* to the conduit 41 which in turn is connectedto the chamber 39. Fixed to the rod is a spring cage 94 carrying three springs ,85 spaced approximately 120 apart, which springs. bear against a stopmemberst the form. of an annulus surrounding the rod 8-5 and; fixedinthe sleeve 83. Three additional springs 91 are post tionecl: the member fi lbetweenithe springs 95 and bear against a second annular step so 98'. fixedi-n the otherend oi sleeve -9;,t,-., Al the:

springsextend beyond the cage 54, dampen ing movement of. the rodto therightor left isperm-itted before-the cage comes into direct contact with the stopmembers.-' The sleeve is provided a: longitudinal-passage Elli which opens into achamber i109,- wh-ich'. in: turnopens, to theinterior of the easingv member. I'll. Thus, when the piston. 84- isv movedto the right, as seen in Figures 2 and i, operatingflu-id pressure is cut off from' the openings 91' and the; sleeve is subiected to operating fluid pressure; to move the sleeve.- to the left, compressing the dampening springs When this occurs flu-id in the cham-- ber 39 isdrained therefrom through the passage M, openings 94,. space 93}, and chamber I00 tothe interior of the casing.

A. follow-up member ill I: is pivotally-mounted at $02 in therelief valve-casing andh-asits lower and W364 bearing against the annular ring fit oi the Wobbler while its upper biiureated end- 83; bears against the stopmember l Variable control oil pressure is suppliedfrom a controlsource- (not; shown) by means of a duit I65 through an outlet pressurerelief' valve mil inai manner to be hereinafter, explained and directed to-a chamber I451: at the right; of' the: b'orenBG: through themed-tunic we; Variable control oil-pressure. in tl chai. 4:01 servesetocmoveathe piston fi l to-the left shown,- uncovering the, openings ill-and them incommuni-cation: with operating. 0' pre sure in the .conduitB to inz-zrease the to the left, allowing the sleeve to s sit in follow-up manner under; the tension of the springs 91. Similarly, should the Wobbler angle increase without decrease ,in operating fluid: pressure inthe chamber 39, the-follow-up member l liwill be pivoted the directionjust described further to decrease the tension'of the springs 91 and to increase the: tension of springs $5 id thus to.

shiftthe sleeve Ell slightly to the, left, mu t operating fluid.

Mounted .on the relay valve is, aprimi-ng valve I I0 having. a chamber 1-! i connected tothe chant her It)? by means-of a passage H2. A piston H3 is reciprocably mounted in the bore.- I-M. of

the priming. valve and urged to the position show-n.

by spring H5. The closed end of the pistonll-B is provided with an orifice-- H 6- in communication with the chamber in and the interior Offlihf} piston. Aplurali-ty or openings HT is provided in the sidewalls of the piston, the openingsbeing isplace merit oi the pump. The dampeningsprings be is in communication with a plurality of openings H9 formedin a sleeve I29 in which the piston reciprocates. The openings I IS-are in communication with the left hand end of the bore H4, which in turn is in communication with the chamber I00 through pass-age I2I. The tension of the spring is such as to permit air in the variable control oil circuit topassthrough the orifice M6, the opening [I], the annular grooves 'and bore and-into the passage I2 I After air has beenexhausted from the variable control oil system and only oil is flowing into the chamber 96, the dih'erential pressure across the orifice H6 increases with the changein the density of the fluid to a point sufficient to overcome the tension of the spring to move the piston H3 to-the left, closing off communication between the annular groove H8 and the openings H9. Once pressure is' established in thevariable control oil circuit the primingvalve remains closed during operation of the pump and control.

Outlet pressure relief valve The outlet pressure relief valve I06 comprises a casing I38 having a bore I3I therein in which are slidable a plurality of pistonlike members I 32. As seen from the drawings, each of the pistonlike members is provided with a first portion in sliding contact with the bore and with a reduced portion 533 at one end in contact with the first portion of the next adjoining memher. The reduced portions I33 provide. a space I3 3 between each pair of pistons, which space is in communication with an annular groovesli-lli an individual jet to supply fuel thereto. In order to safeguard the pump and fuel system of such an engine it is desirable to incorporate an outlet pressure relief valve to limit the maximum pressure in any outlet and to decreasefuel delivery to all nozzles equally, should pressure exceed maximum in any outlet. ,Thus, the device;

of this invention serves to limit engine output when a nozzle becomes inoperative and without subjecting the turbine structure to a condition of. non-uniform heat distribution. 7

To this end, the rightmost piston member. I32. bears against a spool valve 36 which is provided with two end portions l3? and I38 and a central portion 54?! in sliding fluid tight engagement with the bore I3! and with a reduced portion I39- between the end p01tio1rt38-and the central portion Hill. The end portion I38 bears against a stop member I l! resiliently urged thereagainst by means of a spring M2 bearing against a member M3 in the right hand. end-of the bore and.

against a shoulder portion I44 secured to the member Ml. The tension of the spring I 52 is sufficient to maintain all of the members Home pressure, connects to an annular groove I5 1 formed in the casing which in turn is connected by. means of a plurality of passages I5I to the portion of the bore l3 la in which the reduced" portion !39 is located. Another annular groove I53 is also connected to the portion 131la5through 7 a plurality of passages I54 and connects with the conduit I08 connected to the control chamber H11 in the relay valve. With the valve in the position shown in Fig. 2 variations in the control oil pressure are conducted directly through the outlet pressure relief valve to the chamber IBI to shift the piston 84 therein to control the displacement of the pump.

Should the pressure in any outlet exceed the maximum desired value, such pressure in any space I34 will serve to overcome the tension of the spring I42 and to shift all of the members in the bore located between such space I34 and the spring, including the valve I 35. Movement of the valve causes the enlarged portion I49 to cover the openings 1 while simultaneously causing enlarged portion I38 to uncover an annular groove I56 in the right hand portion of the bore. The annular groove I55 is connected by means of a plurality of passages I51 to the interior I58 of that portion of the bore in which the spring I42 is located. The portion I58 is in turn connected by means of a drain I59 to the gear case, and thus variable control pressure in the chamber IBI is drained to the tank and the piston valve 84 moves to the right under the action of the control spring 81. Obviously, the effect of movement of the piston valve 8-4 to the right is to tank the hydraulic fluid under pressure from the cylinder 39 to permit the springs 34 to shift the Wobbler to neutral position.

If desired, of course, the outlet pressure relief valve maybe connected in series with the relay valve to tank the operating fluid directly through movement of the spool valve I rather than indirectly through reduction in variable control oil pressure.

Control oil leaking past the portion I49 enters the portion I3Ib of the bore to the left of the portion I and enters an annular groove I6I which is in communication with said portiontoward neutral position, fluid operated means opposing the biasing means and operating to increase the Wobbler angle to increase the displacement of the pump, an outlet pressure relief valve having a bore, a plurality of piston-like members with each member having a portion in fluid-tight sliding engagement with the bore and a reduced portion in contact with another member to provide a' space between the first portions of adjacent members, means connecting each outlet with the bore at said spaces to subject each member to the opposed pressure in two outlets, a spring holding the members against movement in the bore under normal operating outlet pressure and yieldable under excessive pressure in any outlet to permit sliding movement of a member subjected thereto, a source of control fiuid under pressure, a source of operating fluid under pressure, a relay valve connected to the source of operating fluid, said relay valve having a control fluid chamber and a valving member movable in response to increasing control fluid pres sure in the chamber to direct operating fluid to the opposing means to increase pump displacement and said valving member being movable in response to decreasing control fluid pres: sure in the chamber to tank operating fluid from the opposing means, a passage connecting the source of control 'fluid to one end of the relief valve bore, a second passage connecting said end of the bore to the control chamber, a third passage connecting said end of the bore to a drain, and a control variein said end of the bore, said control valve being in contact with a pistonlike member and movable therewith to control the passages.

2. A control for a multiple outlet Wobbler type pump comprising a source of control fluid, means biasing the Wobbler toward neutral position, a source of actuating fluid, control means connected to the source of actuating fluid to be operated thereby in opposition to the biasing means to increase the wobbler angle to increase the displacement of the pump, a member movable in response to changes in control fluid pressureto control the connection between the source of actuating fluid and the control means, an outlet pressure relief valve having a bore, a plurality of piston like members with each member having a portion in fluid-tight sliding engagement with the bore and a reduced portion in contact with another member to provide a space between the first portions of adjacent members, means connecting each outlet with the bore at said spaces to subject each member to the opposed pressure in two outlets, a spring holding the members against movement in the bore under normal operating outlet pressure and yieldable under excessive pressure in any outlet to'permit sliding movement of a member subjected thereto, a passage connecting the source of control fluid to one end of the bore, a second passage connecting said end of the bore to the member, and a control valve in said end of the bore, said control valve being movable with movement of a member to control the passages.

3. A control for a multiple outlet Wobbler type pump comprising means biasing the Wobbler to- Ward neutral position, a source of actuating fluid under pressure control means connected to the source to be actuated thereby in opposition to' the biasing means to increase the Wobbler angle to increase the displacement of the pump, an outlet pressure relief valve having a bore, a plurality of piston-like members in the bore with each member having a portion in fluid-tight sliding engagement with the bore and a reduced portion in contact with another member to provide a space between the first portions of adjacent members, means connecting each outlet with the bore at said spaces to subject each member to the opposed pressure in two outlets, a spring holding the members against movement in the bore' under normal operating outlet pressure and yieldable under excessive pressure in any outlet to permit sliding movement of a member subjected thereto, and valve means controlling the connection between the source and "the control means operating in response to movement of a member to divert actuating fluid from the control means to permit the biasing means to shift the Wobbler to neutral position.

4. A control for a multiple outlet variable displacement pump comprising means for controlling pump displacement, an outlet pressure relief valve having a bore, a plurality of piston-like members in' the bore with each member having a portion in fluid-tight sliding engagement with the bore and a reduced portion in contact with another member to provide a space between the first portions of adjacent members, means connecting each outlet with the bore at said spaces to subject each member to the opposed pressure in two outlets, a spring holding the members against movement in the bore under normal operating outlet pressure and yieldable under excessive pressure in any outlet to permit sliding movement of a member subjected thereto, and means operating in response to movement of a member to actuate the control means to reduce pump displacement.

5. A control for a multiple outlet wobbler type pump comprising means biasing the wobbler toward neutral position, a source of actuating fluid under pressure, control means connected to the source to be actuated thereby in opposition to the biasing means to shift the wobbler to a strokeimparting position, a plurality of members each subject to the pressure in two outlets and movable in response to differences in pressure between said outlets, and means controlling the connection between the source and the control means and operating in response to movement of a member to divert actuating'fluid from the control means to permit the biasing means to shift the wobbler to neutral position.

6. A control for a multiple outlet variable displacement pump comprising means for controlling pump displacement, means sensing the pressure in each outlet and movable in response to excessive pressure in any one of the outlets and means operating in response to movement of the movable means to actuate the control means to reduce pump displacement.

7. A control for a wobbler type pump comprising a wobbler biased toward maximum stroke position, an annular cylinder, an annular piston in the cylinder and contacting the wobbler, spring means urging the piston toward movement in a direction to shift the wobbler to neutral position, a relay valve having a bore, a first passageway in the bore communicating with a source of operating fluid under pressure, a second passageway in the bore communicating with the annular cylinder, a drain outlet from the bore, a first valve member movable in the bore and having a port in constant communication with the second passageway, a second valve member controlling the port and movable in the bore in response to a variable control force to direct operating fluid to said cylinder to move the piston against the tension of the springs, a follow-up member movable with changes in wobbler position and dampening means resiliently connecting said valve members to each other and to the follow-up member for movement together.

8. A control for a wobbler type pump comprising a wobbler biased towards maximum stroke position, an annular cylinder, an annular piston in the cylinder and contacting thewobbler, spring means urging the piston toward movement in a direction to shift the wobbler to neutral position, a relay valve having a bore, a first passageway in the bore communicating with a source of operating fluid under pressure, a second passageway in the bore communicating with the annular cylinder, a drain outlet from the bore, a sleeve valve member movable in the bore and having a port in constant communication with the second passa-geway, a piston valve member controlling the port and movable in the bore in response to a variable control force to direct operating fluid to said cylinder to move the annular piston against the tension of the springs, a follow-up member bearing against the sleeve valve and movable with changes in wobbler position, and a plurality of dampening springs resiliently connecting said valve members to each other and to the followup member for movement together.

9. A servo type control valve for a wobbler type fluid pump comprising fluid operated means for controlling the wobbler angle, a valve having a bore, a piston valve having a valving land slidable in the bore, means for applying a variable control force to the piston valve to slide the piston valve in the bore, a sleeve valve slidable in the bore and having a valving port controlled by the land, fluid passageways controlled by the land and connecting the control means with a source of operating fiuid under pressure and a drain, an arm movable with changes in wobbler angle and bearing against the sleeve valve, and a plurality of dampening springs having both ends-bearing against the sleeve valve and being connected to the piston valve resiliently to connect said sleeve valve and the piston valve together for movement with the arm in a follow-up manner.

10. A servo type control valve comprising a valve casing having a bore, a piston valve having a valving land slidably mounted in the bore, means for applying a variable control force to the piston valve to slide the piston valve in the bore, a sleeve valve slidable in the bore and having a valving port controlled by the land, a control spring, a control rod connecting the spring to the piston valve for operation in opposition to the control force, a dampening spring secured to the rod, an arm movable in response to changes in position of the member to be controlled, a first stop secured to the sleeve valve and located intermediate one end of the dampening spring and the arm, and a second stop secured to the sleeve valve and located at the other end of the dampening spring.

11. A servo type control valve comprising a member movable in response to a variable control force to move a member to be controlled, a second member movable in a follow-up manner with the first member in response to movement of the member to be controlled, resilient means operating against the first member in opposition to the control force, and a dampening spring connecting the first member to the second member, said spring operating against the first member in opposition to increases in the control force and movable in a follow-up manner with movement of the member to be controlled.

LUDWIG T. STOYKE.

M file of this patent:

UNITED STATES PATENTS Name Date Manly et al May 4, 1915 Number 

